Hollow Core–Shell Cu2−XS@Bi4o5I2 S-Scheme Heterojunctions with Wide Spectral Response and Strong Photothermal Effect for Efficient Photocatalytic H2 Production

Abstract

The rational design and assembly of heterogeneous photocatalyst nanostructures represent an advanced strategy for the efficient conversion of solar energy into chemical energy. In this study, a hollow core–shell cube 45%-Cu_2−xS@Bi₄O₅I₂ S-scheme heterojunction was constructed using an in situ growth deposition method. Owing to its rough surface and hollow polyhedron structure, this unique catalyst exhibits a large specific surface area and multidimensional active sites. Under the synergistic effects of band excitation and plasmon resonance, 45%-Cu_2−xS@Bi₄O₅I₂ demonstrates broad spectral absorption ranging from ultraviolet to near-infrared light, along with strong photothermal conversion performance. Simultaneously, the S-scheme heterojunction structure provides a multichannel charge transfer pathway, facilitating efficient charge separation and inhibiting electron–hole pair recombination driven by the built-in electric field. Furthermore, the photothermal effect generated by Cu_2−xS further enhances charge transfer and surface reaction kinetics, enabling 45%-Cu_2−xS@Bi₄O₅I₂ to achieve an excellent hydrogen evolution yield of 2765.3 μmol g⁻¹ h⁻¹ (28.3 times that of Bi₄O₅I₂) while maintaining good stability. This work offers a novel approach for the generation of renewable hydrogen energy and the design of highly active photocatalysts.